Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['t', 'h', 'Y', 'r', '2193', 'd', '851']

20, 8, 25, 18, 2193, 4, 851